Housing for light-actuated switches



July 3, 1928.

I. E. M CABE HOUSING FOR LIGHT ACTUATED SWITCHES Filed Jan. 10, 1927 5 Sheets-Sheet INVENTOR. [RA 1:. M CABE BY W M ATTORNEYS.

July s, 1928. 1,675,898

I. E. MCCABE HOUSING FOR LIGHT AGTUATED SWITCHES Filed Jan. 10, 1927 5 Sheets-Sheet. 2

INVEXTOR. /R/7 E. M G/75E A TIORXEYS July 3, 1928.

l. E. M CABE HOUSING FOR LIGHT ACTUATED SWITCHES Filed Jan. 10, 1927 5 Sheets-Sheet 3 HOUSING FOR LIGHT ACTUATED SWITCHES Filed Jan. 10, 1927 5 Sheets-Sheet 4 IN V ENTOR. [RA E M CABE BY W M ATTORNEYS.

July 3, 1928.

I. E. M CABE HOUSING FOR LIGHT ACTUATED SWITCHES Filed Jan. 10, 1927 5 Sheets-Sheet INVENTOR. IRA E14 CABE /2am ATTORNEYS.

Patented July 3,1928.

IRA E. MCCAIBE, OF CHlICAGO, ILLINOIS.

HOUSING FOR LIGHT-ACTUATED SWITCHES.

Application filed January 10, 1927. Serial 1%. 160,164.

This invention relates to electric control switches and more particularly to a safet housing for a light actuated control switc vfor oil burning and similar devices.

The type of switch for which this improved mounting is provided is fully illustrated and described in my prior co-pending application Serial Number 133,868, filed September 7 1926. Briefly, this light actuated switch comprises two sealed containers,

preferably of glass and approximately'the shape of electric light bulbs, with a restricted portion connecting the lower ends of the containers and having a mercury seal therein. One of the containers supports two spaced-apart electrodes, extending through the.walls thereof in one direction and terminated within the interior of the container 4 in the other direction, a short distance above the surface of the mercury seal. The walls of this container are formed of a medium transparent to rays of the visible'spectrum while the walls of the other container are formed of a medium adapted to absorb the rays of the visible spectrum, and in absorbing such light rays their energy is. transmuted into heat increasing the internal pressure in that container and causing the mercury seal to mov into the other container and to make an electric contact between the two electrodes, and upon the removal of I portation and use the source of light the internal pressures equalize within the two containers causing the seal to return to normal and break the electrical connection between the-two elec-- trodes.

This improved mounting or housing for this type of switch is particularly advantageous wher the switch is a part of the electric control system'for a domestic liquid fuel heating plant and it not only provides a means for mounting the delicate andfragile switch which will protect it during transbut the manner of attach ment in operative relation to the other parts of such a system, as above referred to, 1s such that the switch must be placed 1n an inoperative position before the housing can be'secured or removed from its place of attachment for operation as a part of such a system.

' While the preferred form of this invention is illustrated upon the accompanying sheets of drawing, yet it is to be understood that minor detail changes may be made therein without departing from the scope of this invention.

In the drawings:

Figure 1 is a View in side elevation showing a commercial oil burner to which this invention has been attached, with the domestic heater shown in section with the other controls in outline and the electric wiring of the system in dia ram.

Figure 2 is a ragmentary perspective view, looking from the side opposite that shown in Figure 1, with parts broken away.

Figure 3 is a top plan detail view of the housing, shown in Figure 2. x

Figure 4 is a view in front elevation of Figure 3,

Figure 5 is a view in transverse vertical section taken on the line 55 Figure 4, looking in the direction of the arrows.

*igure 6 is a view similar to Figure 3 showing the relation of the parts when unlocked or adapted to be detached or secured to the burner. v

Figure? is a view similar to Figure 4 showing the relation of the parts when unlocked, as shown in Figure 6.

The commercial oil burner system illustrated in Figure 1 is fully illustrated and described in my prior co-pending application Serial Number 153,022, filed December 6, 1926, and briefl comprises a domestic heater or furnace ll to which a domestic liquid fuel burner has been attached by inserting the draft pipqD into the combustion chambei' thereof and through which liquid fuel and air are; supplied by the motor M and a fan blower in casing F, the flame beingignited at the nozzle N by an i nition device I connected to a spark coil A knife switch K is preferably interposed in the commercial circuit between the motor and source, one line therefrom leading to one pole of the motor and the other line therefrom leading through a room thermostat T, boiler or furnace controlB and safety control S to the other pole of the motor. The safety. control switch S is connected to the spark coil C and light actuated switch in the housing L and is so constructed that when th commercial circuit is closed through the thermostat it will close a circuit through the motor and spark coil to ignite the burner flame and if the flame fails to ignite will operate a safety switch in the' motor circuit to open the motor circuit until manually closed, but if the flame ignites will then operate, by the actuation of the light switch, to shunt out the safety switch and break the spark coil circuit, and after ignition should the burner flame become extinguished the light switch will operate to allow the full strength of the commercial current to operate the safety switch, as above described.

As shown in Figure 1, the housing L of the light switch is in the form of a rectangular box, and as shown in the other figures, is formed with a plate 1 on the side furthest from the draft pipe D which plate is bent over at the top to form a closure 2 adapted to tangentially engage and rest upon the top of the draft pipe D, and bent over at the bottom 3 a sufficient distance below the top to receive the light switch, hereinafter described, and then bent upward parallel to plate 1 to form a closure 1 between the bottom3 and under side of the draft pipe 1). Plates 5 and 6 are secured at each end to form closures between the top, bottom and sides of the housin and adjacent surfaces of the draft pipe. The draft pipe D is cut out as shown and is formed with a lug d depending from the center of the cutout portion of the upper side. The side closure 4 is provided with engaging hooks 7 adapted to engage the lower body of the draft pipe and support the housing in close contact therewith. The upper closure 2 is provided with a locking member 8 pivoted on the under side thereof and having a hook portion 9 at one end adapted to engage the lug d of the draft pipe and hold the housing securely in contact with the draft pipe on all four sides. The end on the other side of the pivot of the locking member 8 is forked and bent down at right angles to form two spaced-apart lugs 10.

The light switch herein illustrated comprises two enlarged containers ],1 and 12 somewhat in shape of electric light bulbs, with container 11 drawn to a projecting tip 13 at its top and container 12 having a reentrant portion formed in its top through which two electrodes 14 and 15 pass and are sealed therein in spaced-apart relation, with their exterior ends connected to leads 16 and 17 adapted in turn to be connected to the safety control switch S. Each container is reduced symmetrically in diameter to form restricted lower ends each of which is drawn to a tip 18 and the two restricted lower portions above their respective ends are joined by a connecting member 19 having a restricted bore communicating with the interior of both containers. A mercury seal 20 is contained within this bore and the lower ends of the respective containers and is of such an amount that when the center line between the containers is vertical the level of the surface of the mercury in both containers will lie in the same horizontal lane below and out of contact with theower extremities of the electrodes 14 and 15 so that an electrical connection will not be established between them. The container 11, as above stated, is formed of a medium adapted to absorb the rays of the visible spectrum which will emanate from the burner flame whenv ignited and in so doing will increase the internal pressure to cause the surface of the mercury 20 to become depressed in containerll and move upward in' circuit between the'electrodes 14 and 15, i

any event such a tilting would change the balanced relation between the pressures in the two containers. This tilting of the light switch might easily occur while itis being installed .in place or in removing it from the burner. In order to prevent such an occurrence it is preferable to mount the switch as shown in detail in Figures 4 and 5. Two overlapping container supporting plates 21 and 22 are provided and are adjustably connected to each other at their overlapping edges, in order to make adjustments for irregularities in the formation of the containers, with the lower ends of each bent outward and provided near the extremities thereof with supporting'bearings 23 to engage the lower tips '18 of the containers 11 and 12. The plate 21 is provided with a portion extending upward and bent outward and formed at the end thereof with a supporting bearing 24 for the tip 13 of the container 11. The plate 22 is bent outward at such a point and is cutout so that it will form an embracing arm 25 for the container 12, preferably a short distance below its greatest diameter,- and this embracing arm 25 may be provided with upwardly extending engaging fingers 26, if desired. It is preferable that the metal plates 21 and 22 be of resilient metal which will allow slight adjustment for the bearings'23, embracing arm 25 and engaging fingers 26 to adapt the mountin to irregularities in the construction or $0 mation of different switches.

The supporting p-lates'21 and 22 are preferably mounted upon a pivot 27 passing through and secured to plate 1 of the housing, which pivot may be the upper adjusting member passing through the overlapping edges of sald plates. A bell crank operating loo lever 28 is also mounted at its apex on the pivot 27, with one arm 28 extending upward therefrom adjacent the inner surface of the plate 1, passing through a slot 29 in the top plate 2 and terminated a short distance thereabove. This arm 28 is provided with a lug 30, preferably struck up therefrom, adapted to engage between the depending lugs 10 of the locking member 8. The other arm 31 of the bell crank operating lever passes between plate land the supporting plate 22, and is adjustabl secured at. the rear of said plate, prefera ly by providing an arcuate slot 32 in said arm 31 and passing a bolt 33 through plate 22 and through said slot and securing the two in adjusted position by a nut upon said bolt.

The relation between the operating lever and locking device is such that when the end of the arm 28 extending above the house ing is moved to the left, as shown in Figures 6 and 7, the locking member will be moved to unlock the housing from the draft pipe D so that the housing with the arm 28 in this position may be placed in position or removed therefrom, and when the arm 28 is moved to the right as shown in Figures 2, 3, and 4 the housing will be locked in position upon the draft pipe. The arm 30 of the operating lever is so adjusted in relation to the supporting plate 22 that when the arm 28 is at the end of its travel to the right the center line between the containers will be vertical and the level of the mercury in container 12 will be out of contact with the terminals 14 and 15. So that whenever the operating arm 28 is moved to the left to unlock the housing, the supporting plates 21 and 22 and the llght SWItClI mounted thereon will be tilted to the left So that the weight of the mercury of the seal will cause it to flow into container 11 away from the electrodes in container 12, thereby preventing the establishment of an electrical connection between the electrodes while the housing is being attached-or detached upon the draft pipe.

To insure the centering of the housing in locking the same to the draft pipe D it 1s preferable to provide slots body of the draft'pipe for the reception of the hooks 7 and also provide guiding and switch protecting members 35 in the form of bowed strips of metal secured at their ends to the top plate 2 and side plate 4,

respectively, and adjacent each end plate 5 and 6.

This improved housing provides a means of mounting thelight switch, which will protect it in transportation and operation, looks it securely in place, prevents its being removed while the circuit is closed therethrough and prevents the closing of the circuit during removal. and mounts the switch in connection with the burner in a place 34 in the lower where the light from the ignited fuel issuing at the nozzle will positively fall upon the light-absorbing container.

What I claim is:

1. In a housing for a light actuated electric switch, means for mounting said switch and supporting it within the housing, means for rotating said switch mounting to place said switch in an inoperative position, and means for securing said housing with said switch in operative position co-acting with said latter means. a

2. In a housing for a light actuated electric switch, means for mounting said switch and supporting it within the housing, and means for moving'said switch mounting to place said switch in an inoperative position for moving'said switch into operative position, means for securing said housing in. place co-operating with the means for moving the mounting to secure the housing and imultaneously moving the switch into operative position. a

' 3. A housing for a light actuated electric switch including means for mounting said switch and supporting it within the housing, means for moving said switch mounting to place said switch in an inoperative position for moving said switch into operative position, means for securing said housing in place co-operating with the means for mov-' ing the mounting to simultaneously move the switch into operative position, and to simultaneously release the housing and move the switch into inoperative position.

4. In a liquid fuel domestic heating system' an electrically operated fuel burner adapted to supply liquid fuel through a nozzle and air under pressure through a draft pipe to the combustionchamber of a heater, electric controls for said fuel burner including a switch adapted to be actuated by the presence of light from the burner flame, a detachable housing for said switch adapted to mount the switch within the draft pipe in line with the rays of light emanating from the ignited fuel, means upon the draft pipe to be engaged by attaching means upon the housing, a rotatable support for-the light switch carried upon the housing, a locking member mounted upon the housing co-operating with the means upon the draft pipe for locking the same in place, means for simultaneously actuating said locking means and movable support arranged when in unlockedposition to move the switch into inoperative position.

5. In a device of the character described, a housing adapted to fit about an aperture in the draft pipe of a liquid fuel burner and engage the body thereof, a locking member upon the housing adapted to secure the same in place upon the draft pipe, a light actuated switch, a mounting thereof pivotally arranged within the housing and adapted to be tilted about the pivot point to operative and movement of the operating lever in the and inoperative positions, an operating lever opposite direction moves the locking member 1 adapted to engage the locking member and into locked position and the light switch adjustably attached to the light switch into operative position.

6 mounting in such a manner that movement Dated at Chicago Illinois this 7th day of of the operating lever in one direction tilts January, 1927. the switch to inoperative position and moves the locking member to the unlocked position IRA E. MCCABE. 

